Blue trisazo dye.



ADoLF ISRAEL AND RICHARD KOTHE,

PATENT OFFICE.

OF ELBERFELD, GERMANY, ASSIGNORS TO THE FARBENFABRIKEN OF ELBERFELD COMPANY, OF NEW YORK.

BLUE TRlSAZO DYE.

SPECIFICATION forming part of Letters Patent No. 648,623, dated May 1, 1900.

Application filed January 13, 1900. Serial No. 1,313. (Specimens) 'para-phenylenediamin, with one molecule of Oleves alphanaphthylaminbetasulfonic acid, (1. 6 or 1.7;) secondly, rediazotizing the resulting amidoazo compound 5 thirdly, combining the diazo compound thus obtained with a second molecule of one of the said Olves acids; fourthly, again diazotizing the resulting amidoazo dyestuff; fifthly, coupling the diazo compound thus produced with a naphtholmono or disulfonic acid, and finally treating the resulting trisazo dyestuff with caustic alkalies in order to split off the aoidyl group.-

The new dyestuffs produced in the abovedefined manner are alkaline salts of acids having the following general formula (w representing in this formula a hydrogen atom which may be substituted by a sulfo group) and are dark powders which dissolve in water with from reddish-blue to blue color. They dye unmordanted cotton in general blue shades, (these shades varying from reddish-blue to grayish-blue.) When on fiber,

these dyestuffs can be further diazotized and coupled with betanaphthol, blue shades of considerable value, which are distinguished by their fastness to light, being thus obtained.

In carrying out our new process practically we can proceed as follows, the parts being by weight: Fifteen parts of acetylpara phenylenediamin are diazotized in the usual manner with the aid of twenty parts of muriatic acid (testing 23 Baum) and seven parts of sodium nitrite. The resulting diazo solution is stirred into a solution prepared I from twenty-five parts of the sodium salt of (1.6,) twenty parts of crystallized sodium which solution has been cooled to 10 centigrade. After the formation of the dyestuff has been finished the latter is separated from the mixture by the addition of common salt and isolated by filtration. The coloring-mathundred parts of water and then with thirtyfive parts of a muriatic acid of 20 Baum. The resulting mixture is cooled and then sodium nitrite. When the diazotization has been finished, the separated diazo compound is filtered off. Subsequently it is mixed with a suitable quantity of water and introduced into a watery solution of twenty-five parts of the sodium salt of Cleves 1I6-naphthylaminsulfonic acid, to which a suflicient quantity of sodium acetate has been added. The resulting mixture is stirred for several hours until the formation of the disazo dyestuif having the formula o H H will be finished. This dyestuff is separated with the aid of common salt and filtered off. Subsequently it is carefully mixed with water and thirty-five parts of a muriatic acid of 20 Baum. To the resulting mixture a solution of nine parts of sodium nitrite is slowly added while stirring and cooling. The diazo compound thus produced is isolated by filtration, mixed with water, and then stirred into solution is mixed with one hundred and fifty three per cent. of NaOH) and boiled for a short while. Finally one hundred and eighty parts of common salt and eighty parts of a Cleves alphanaphthylaminbetasulfonic acid,

ter thus obtained is carefully mixed with five an icy-cold solution of twenty-five parts of acetate, and five hundred parts of water,

slowly mixed with a solution of nine parts of solved in one thousand parts of water, which parts of a strong soda-lye (containing thirty- IOO twenty-threc-per-cent. hydrochloric acid are added. The resulting precipitate is filtered, pressed, dried, and pulverized. It is the sodium salt of an acid having the formula pure-blue shades being thus produced, which are fast to washing and distinguished by their fastness against the action of light. 7

Having now described our invention and in what manner the same is to be performed, what we claim as new, and desire to secure by Letters Patent, is-

1. As new articles of manufacture the new trisazo dyestuffs which are alkaline salts of acids having the general formula NH, soar soar .1; representing in this formula a hydrogen atom that may be substituted by a sulfo group, and which are dark powders soluble in water with from reddish-blue to blue color, dyeing unmordanted cotton from reddish blue to grayish-blue shades, which when on fiber can be further diazotized and coupled with betanaphthol, shades of considerable value being thus obtained which are distinguished by their fastness to light, substantially as .hereinbefore described.

2. As a new article of manufacture the new trisazo dyestuff being an alkaline salt of an acid having the formula which in the form of the sodium salt is a black powder, soluble in water with a reddish-blue color which changes into pure blue on the addition of a strong soda-lye, insoluble in concentrated hydrochloric acid and in alcohol, being dissolved by concentrated sulfuric acid (66 Baum with a blue color which is changed into reddish-blue on-the addition of a small quantity of ice, dyeing unmordanted cotton reddish-blue shades which shades can be further diazotized and developed on the fiber by means of betanaphthol, beautiful blue shades being thus obtained which are fast to washing and are distinguished by their fastness to light,substantiallyas hereinbefore described.

In testimony whereof we have signed our names in the presence of two subscribing witnesses.

ADOLF ISRAEL. RICHARD KOTHE.

Witnesses:

Or'ro KONIG, J. A. RITTERSHAUS. 

